mfd: Add support for RICOH PMIC RC5T619 on odroid-pi

Ricoh power management IC  RC5T619 contains is multi
functional device having multiple sub devices inside this.
This device has multiple dcdc/ldo regulators, gpios, interrupt
controllers, on-key, RTCs, ADCs, Charger, Fuel Gauge.
This device have 5 DCDCs, 12 LDOs, 5 GPIOs, 8 ADCs, 1 RTC, 1 Charger, 1 Fuel Gauge etc.